查询构建器上的Laravel中间数据类型

i have a date inside a query in laravel. query builder doesn't read my date as a string. i cant put a variable inside the query so i can't use date->format nor explode string..

here is my code..

if(isset($input['time']) && $input['time'] != '')
{
    //Useless, laravel cant read this
    $wew = explode('/', $input['time']);
    $time = $wew[0]."-".$wew[1]."-".$wew[2];

    $actlist = DB::table('activity')
    ->join('activity_details', function($join)
    {
        $join->on('activity.id','=','activity_details.activity_id')
             ->where('activity_details.time','>=', (date(str_replace('-','-',Input::get('time')).' 00:00:00',time())) )
             ->where('activity_details.time','<=', (date(str_replace('/','-',Input::get('time')).' 23:59:59',time())) );
    })
    ->orderBy('activity.id', 'desc')
    ->paginate(Config::get('app.conf')['pagin']);
}

the $wew = explode('/', $input['time']); returns undefined

where did i go wrong?